Assessment of chloride-induced reinforcement corrosion protection of modified sulfur polymer composites. (25th January 2021)

• Record Type: Journal Article
• Authors: Rasheed, Quaid; Ali Sikandar, Muhammad; Hanif Khan, Muhammad; Akash, Kalsoom; Nasir, Hassan; Jehan Khan, Beenish
• Is Part Of: Construction & building materials. Volume 268(2021)
• Publication Date: 2021-01-25
• Subjects: Corrosion -- Rebar -- Sulfur -- Half-cell -- SEM -- FTIR; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2020.121086
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Microfillers enhance the mechanical properties of sulfur-based mortars. Microfillers reduce the sorptivity of sulfur-based mortars. Microfillers enhance corrosion protection of steel rebars in sulfur-based mortars. SSM or SMM has better corrosion inhibition properties than SM or SFM. Abstract: The present study deals with the corrosion behavior assessment of steel reinforcing bars embedded in modified sulfur polymer-based mortars with and without microfillers. Modified sulfur was used as the primary binder, while silica fume, metakaolin, and fly ash were used as the microfillers in the sulfur polymer composites. The comparison was made with Portland cement mortar (CM). The modified sulfur polymer mortars formulations used were plain sulfur mortars (SM), sulfur-silica fume mortar (SSM), sulfur-metakaolin mortar (SMM), and sulfur-fly ash mortars (SFM). The reinforced samples were exposed to 5% calcium chloride (CaCl2 ) solution for 52 weeks (~365 days). The corrosion states of rebars embedded in sulfur, as well as Portland cement mortars, were estimated in terms of electrical resistivity (ER), half-cell potentials, corrosion current density based on linear polarization resistance (LPR) test, and visual inspection of steel rebars and mortar samples. Besides, comprehensive analysis based on Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy were also performed on samples collected from the steel-mortar interface of all specimens. The results revealed that the rebars embedded in sulfur-based mortars underwent less corrosion-related deterioration compared to Portland cement mortars. Moreover, the inclusion of microfillers improved the corrosion inhibition performance of sulfur-mortars. Furthermore, deterioration effects were observed to be lower due to improved sorptivity values. The corrosion inhibition effect of mortars was observed to be decreasing in the order SSM > SMM > SM > SFM > CM.